Stay-bolt for boilers.



E; l. DODDS.

STAY BOLT FOR BOILERS.

APPLICATION FILED NOV. 30.1914.

1 l 88, 9 l 1 Patented June 27, 1916.

EL {Pi- Q I 9 s i 9 WITNESSES INVENTOR ,4//r 1 a 1 I10! Z6 w Allormy Tun COLUMBIA PLANOGRAPH c0, WASHINGTON. n. c.

1 T TAE PATENT ETHAN I. DODDS, 0F PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO FLANNERY BOLT COMPANY, OF PITTSBURGH, PENNSYLVANIA.

STAY-BOLT FOB BOILERS.

To all whom it may concern:

Be it known that I, ETHAN I. Donns, a citizen of the United States, and a resident of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Stay-Bolts for Boilers; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to an improvement in stay bolts for boilers.

Heretofore bolts have been made up of a plurality of independent members, or with the shank or portion thereof between the heads composed of a plurality of separated members, but experiments have demonstrated that bolts so constructed will buckle or become distorted while applying them to the boiler sheets.

The object of this invention is to provide a bolt that will be flexible laterally, to accommodate itself to the lateral twisting or torsional strains imparted to it by the unequal movements of the boiler sheets, but which will be sufliciently rigid against longitudinal stresses to prevent any buckling or bending of the shank while the bolt is being applied or driven into place.

With this object in view my invention consists in the details of construction as will be more fully explained and pointed out in the claims.

In the accompanying drawings, Figure l is a view in longitudinal section through a die showing a slotted stay bolt blank therein; Fig. 2 is a view in transverse section through the die and blank showing a punch for forming the slots; Figs. 3 and at are similar views showing tools for slotting which may be used instead of a punch; Fig. 5 is a view in elevation of a bolt slotted by the device shown in Fig. 8; Fig. 6 is a similar view showing the slots formed by either the punch of Fig. 2 or the slotting device of Fig. &, and Fig. 7 shows the shank of the bolt twisted.

In the manufacture of this bolt, a bar 1 preferably cylindrical is subjected to an upsetting heat and placed, and swaged if necessary, between dies 2, having an opening therein for the entrance of punches 8, and openings for the escape of the slugs 4 punched from the bar, as shown in Fig. 2,

Specification of Letters Patent.

Application filed November 30, 1914.

or between dies having diametrically opposed openings for the entrance of slotting or piercing tools as in Fig. 3, or dies having openings on one side only for slotting or piercing tools 5, the said punching or slotting tools adapted to form openings all the way through the blank.

As shown in Figs. 1, 5 and 6 the slotting or punching tools are arranged to form two slots approximately in the center of the bar, and in line with each other, a comparatively small web 6 being left between the ends of the two slots 8 in order to tie the two mem bers 7 of the shank of the bolt together and prevent them from bulging or separating. The slots 8 extend approximately the length of the shank, and after the blank has been slotted, the dilation of the sides caused by the slotting is reduced and the slots approximately closed while the blank is still hot, but not at a welding heat, by a hammer or other suitable tool or machine thus reducing the diameter of the blank to approximately its original size, without welding together the side walls of the slot.

While the bolt is still hot, or after it has been reheated, but not to a welding heat, it is reduced by hammering or otherwise at its center as shown in Figs. 5 and 6, and after it has been reduced to proper diameter, the shank, or the portion thereof between the heads 9 is twisted about 180 as shown in Fig. 7, so that the two end to end slots will be in the form of a spiral half way around the shank. The heads 9 are then threaded and the tell-tale bore 10 drilled in the outer head.

Experiments have shown that a bolt made in sections is the ideal bolt for connecting boiler sheets, as it is sufliciently flexible to permit of unequal movements of the boiler sheets without unduly straining either one, but they will buckle under collapsing stresses and are not sufficiently rigid in all cases to withstand the vibrations and stresses to which they are subjected. It is also, owing to their flexibility, difficult to apply them to the boiler sheets and particularly so if any of the threads bind. With my construction, the integral web separating the slots and tying the members of the shank together, is suflicient to prevent bulging or spreading of the member under the twisting and torsional strains to which the bolts are subjected when applying them to the sheets,

while the slots lengthwise the bolt shank render the latter sufiiciently flexible that it will be free to yield or give in all lateral directions.

Having fully described my invention what I claim as new and desire to secure by Letters-Patent, is

1. As a new article of manufacture, a stay bolt blank having a plurality of slots eX- tending transversely through same, the said slots being located end to end and separated by a comparatively small web integral with the shank.

2. As a new article of manufacture, a stay bolt shank having a plurality of slots extending transversely through the same, the said slots being located end to end and extending throughout the length of the shank of the bolt, the slots being separated from each other by a comparatively small web integral with the shank.

3. As a new article of manufacture, a stay bolt shank having a plurality of slots extending transversely through same, and approximately the length of the shank, the said slots being separated by a comparatively small integral web, and the shank twisted so that the slots extend in spiral form around the latter.

In testimony whereof, I have signed this specification in the presence of two subscribing witnesses.

' ETHAN I. DODDS. WVitnesses v l/VM. CHARLES BINGHAM, EDWIN SPENCER RYoE.

Copies of this patent may be obtained for five cents each, by addressing the "Commissioner of Patents.

Washington, I). c." 

